Slender, vibrioid to spirally curved rods, 0.1–0.5 × 1.0–3 µm. May form helical chains of two or more cells. Motile by polar flagella. Gram negative. Nonsporeforming. Microaerobic, with respiratory oxidation of succinate, fumarate, malate, lactate, or pyruvate, but not acetate. Oxidase positive. Carbohydrates are not oxidized or fermented. Reduces S0. Fumarate may be fermented under anoxic conditions. Free living, found in freshwater and marine environments. Temperature growth range from 8 to 36°C. Based on 16S rRNA gene sequence comparisons, Sulfurospirillum falls in the family Campylobacteraceae, which belongs in the Epsilonproteobacteria.